Players don't practice fielding at different positions. There are the general field drills that everyone does, like pick ups and throws and catches, stuff like that. And then the better catchers who are expected to stand at slips, gully, point, short extra cover do a lot of close catching to sharpen their reflexes. And then the captain places fielders according to their strengths. Like fielders with good throwing arms (usually the fast bowlers) get placed at third man/ fine leg etc.
If you notice Kapali's fielding at point, you will see that what he is good at is ground fielding. He hasn't taken too many blinders of catches. He just has to practice his catches.